Every river — wide or narrow, fast or slow — eventually meets the sea. Krishna declares that all action, in its entirety, reaches its completion in knowledge. The yajna of knowledge stands higher than any yajna performed with material offerings. Material yajnas have their place, but knowledge is where everything finds its final rest.
This is the central teaching of the chapter. The chapter is called Gyana Karma Sannyasa Yoga for exactly this reason: knowledge is where karma finds its fulfillment, not in accumulation but in understanding. The goal is not more action. The goal is the clarity that makes action free.